* rocm-cmake: remove ldconfig variant
The packages built for `rocm-cmake~ldconfig` and `rocm-cmake+ldconfig`
are identical, so the variant is unnecessary.
The `ROCM_DISABLE_LDCONFIG` option changes how `rocm_create_package`
generates DEB and RPM packages with CPack. rocm-cmake itself uses
`rocm_create_package`, however, this option is has no effect because
Spack does not build the CPack packages. It is also unnecessary on
rocm-cmake, because rocm-cmake does not contain any shared libraries
for ldconfig to configure. The rocm-cmake package is purely composed
of CMake scripts.
* Tighten CMake version dependency
* Improve package description
9a977cb694